Improvement in screw-cutting dies



J'. S. CAMPBELL & T. T. EYRE.

SCREW CUTTING DIES. No.178,409. Patented Junefi, 1876.

J B r Witnesses N nVentOI'S' @gw 2% 6? 455% 681% MPETERS.FHOTOLITNOGRAPHER, WASHINGTON. D C.

UNITED STATES PATENT OFFICE.

JOHN S. CAMPBELL, OF ASTORIA, AND THOMAS T. EYRE, OF SALEM, OREGON.

\ IMPROVEMENT IN SCREW-CUTTING DIES.

Specification forming part of Letters Patent No. 178,409, dated June 6,1876; application filed January 17, 1876.

To all whom it may concern 1 Be it known that we, JOHN S. CAMPBELL,

' of Astoria, Oregon, and THOMAS T. EYRE, of

Salem, Marion, county, State of Oregon, have invented an ImprovedScrew-Plate; and we do hereby declare the following description andaccompanying drawings are snfiicient to enable anyperson skilled in theart or science to which it most nearly appertains to make and use oursaid invention without further invention or experiment.

The object of our invention is to so arrange and apply the dies in ascrew-plate that they can be set to threads of any desired size, and sothat. when the dies are once set they will cut a screw of uniform size,so that the same nut will fit every screw made by it.

Referring to the drawings, Figure 1 is a per-" spective view of ourbolt-cutter. Fig. 2 is a plan view.

Let A represent the stock or screw-plate. For convenience we haveapplied our'invention to a screw-plate in whichthe handles are formed ondiagonal corners of the plate, so as to leave the ends of the plate freefor the passage of the screws which operate the dies. The recess D, orslot in which the dies B 0 move, is made narrower at one end than at theother, so that the narrower die 0 moves in the narrow portion, while awider die, B, moves in the wider portion, thus providing a shoulder, E,on each side of the slot or recess, against which the larger die willstrike when moved toward the smaller die 0. The sides of the slot orrecess are made V-shaped, in the usual way, and the edges of the diesare grooved accordingly, so as to guide the dies and hold them in place.A thumb or lever screw, f, passes through the end of the screwplate A,so that its end will press against the narrow die 0, while anotherscrew, g, passes through the opposite end of the plate, so that its endpresses against the back of the die B. In using this screw-plate, thesize of the screw to be made is first obtained. The narrow die O is thenset, by means of the thumb-screw f, so that when the wider die B isforced up against the shoulder E of the recess D, the screw formed bythe two dies will be of the proper size. The widest die is then movedback, so as to admit the end of the bolt or screw-rod; and, as the screwis finished, the die B is moved up, by means of the screw 9, until itstrikes the shoulders E, thus finishing the screw. These shoulders Eserve as a gage for determining the size of every screw.

When the die 0 is once set, every screw formed by the dies will beuniform as long as the die B is moved up against the shoulders in makingthe threads, and, by shifting the position of the die 0, any desiredsize of screw can be formed.

We thus provide a very convenient screwplate, by which screws in avariety of sizes can be made, and every screw will be uniform, so as toreceive the same nut.

Having thus described our invention, what we claim, and desire to secureby Letters Patout, is-- The screw-plate A. having the recess or slot D,made narrower at one end than at the other, so as to provide a shoulder,E, in combination with the dies B 0, one of which moves in the narrowand the other in the wider portion of the slot, and operated by thescrews f g, substantially as and for the purpose described.

JOHN S. CAMPBELL. [L. s.]

THOMAS TURNER EYRE. [L. 8.] Witnesses:

GEo. H. STRONG,

O. M. RICHARDSON.

